1. Field of the Invention
The present invention relates to soil aerators of the type utilized to penetrate the surface of the earth to provide increased ventilation and facilitate moisture retention.
2. Description of the Prior Art
U.S. Pat. No. 3,794,121, to Drozak, issued Feb. 26, 1974, shows a soil aerator having a cylindrical drum mounted on a framework which is carried by a tractor. A plurality of tubular soil penetrating spikes are mounted on the exterior surface of the cylindrical drum.
U.S. Pat. No. 1,898,214, to Richards, issued Feb. 21, 1933, shows a lawn aerator which includes a drum having a number of small, sharp spikes made of spring steel. The drum may be filled with water or sand to give it sufficient weight.
U.S. Pat. No. 1,370,219, to Miller, issued Mar. 1, 1921, shows a cultivator for aerating top soil, having a plurality of disk or plate members with penetrating prongs that are designed to pierce the earth as the device is moved over the earth's surface.
The spikes or prongs used on aerators in the past have tended to be easily damaged because of the large compressive and bending forces encountered by each of the individual spikes during use, and when engaging hard objects in or on the surface of the ground. The large forces encountered tended to cause the spikes or prongs to wear rapidly and to frequently break or crack. Perhaps more importantly, aerators of the type discussed above had spike arrangements which caused substantial damage to the surface of the soil which is usually planted with grass or other ground cover vegetation.
There exists a need, therefore, for an aerator useful for ventilating soil which has penetrating members which are not easily broken or damaged.
There exists a need for such an aerator having an arrangement of penetrating members which increases the surface area of the soil for contact with oxygen, but which does not damage the root system or vegetation of the planted ground cover.